How many walleye can Storm Lake serve up?
Along with the glacial lake's growing appeal as a recreation tourism site comes greater pressure on the fishery to deliver a good catch to the navy of anglers who visit it.
In past years, the creel studies by the Iowa Dept. of Natural Resources has led to estimates of a fish harvest of 3,000-5,000 annually.
Last year, that estimate leaped to 18,000 fish taken.
"To be honest, that's a little scary to us," veteran DNR fish biologist Lanny Miller says. "Our fishermen don't realize just how many walleye they are harvesting."
The increase comes despite the "slot limit" that was imposed on Storm Lake a little over a year ago to try to increase the number of larger fish developing - the DNR depends on those big mamas to produce the eggs they harvest to populate the hatcheries in the state, for stocking of Storm Lake and other Iowa waters.
The slot limit requires anglers to release the lake's marquee fish in the 17 to 22-inch "slot" back into the water.
The DNR had created computer models projecting what should happen to the fish classes as a result.
"The computer wasn't quite right," Miller admits. The DNR hadn't foreseen the sudden dramatic increase in fishing pressure in 2007.
The concern now is that thousands of walleyes are being reeled in just below the slot size - perhaps meaning that there won't be enough left to form that next generation of big fish.
So the DNR is loading up for another massive stocking program in 2008.
Forget the "fry" baby fish that are barely a speck - they have only about a 1 percent chance of surviving into adult fish here, Miller said.
The cavalry will arrive armed with 17,000 robust eight-inch walleye produced at the Rathbun hartchery, plus 15,000 six-inchers raised at the Spirit Lake hatchery.
The bigger stock fish have up to a 90 percent survival rate.
"In the past, we could never guarantee a particular year class of fish on Storm Lake - well, now we can make that guarantee," Miller said.
In October, the DNR will follow up by stocking 9,000 channel catfish.
The walleye slot limit will almost certainly last for at least three more years on the lake. It will take that long, Miller said, to gather firm data on the impact to the fish population. "If that doesn't work, then we can try something else."
Few anglers are complaining. They love fishing Storm Lake and want to see the population of big fish grown for future years, Miller said. "The kind of fishermen we get at Storm Lake often get a charge out of catching and releasing a 20, 21-inch fish. They know how valuable that big girl is to us, and most of them probably wouldn't think about taking her out of this lake anyway."
Anglers can get away with taking one trophy walleye from Storm Lake, "but it really helps us if they throw it back," Miller said. "You don't have to kill the fish to enjoy fishing."
Despite an estimated 13,000 fish taken in spring and summer 2007, the ice fishing has also been good on Storm Lake, leading Miller to forecast an excellent year for local anglers.
"Even if the walleye aren't biting great - and I have no reason to expect that they won't - the channel catfish are just excellent in Storm Lake, and it might be the best white bass fishing in the state right now," the biologist said.
The DNR is actually encouraging anglers to take white bass from Storm Lake. A very predatory fish, it would not be good for them to become overpopulated, the expert suggested.
The state once stocked northern pike and tiger muskie in Storm Lake, but those days are over.
"The state doesn't even raise tiger muskie any more. And all we can get are very small northern pike - throwing those into Storm Lake would just be like throwing popcorn to children - they would be eaten as soon as they hit the water."
There is always discussion of changing up the fish stocked into the lake, but the current game fish depend on the delicate balance with gizzard shad to feed on. "It scares me to add teeth to this lake," Miller said of other predator fish.
That doesn't mean that an angler may not make a surprising catch.
Generations ago, fishermen had their photos taken with bufflo nearly as large as they were, pulled from the lake where they were native.
"We have actually seen buffalo again, and they are increasing. There are some real hogs down in Storm Lake - we've pulled up 20-30 pound fish that make a real mess of our netting," Miller said.
Every so often, a Storm Lake angler still hauls out a big northern, and not too long ago, a flathead catfish was landed. "These are things you don't expect to see - it makes you wonder if someone has just brought a fish in and turned it loose."
"That is one darn good fishery Storm Lake has," Miller added, "And people have started to recognize that."